There have been many different types and kinds of keyboards for producing signal responses when depressed. For example, membrane keyboards are usually generally flat or planar in configuration. They do not ordinarily have the same type of audible and tactile feedback response as the conventional discrete keys. The keys of membrane keyboards are usually generally flat and have little or no perceivable travel, and thus little or no tactile response is produced when depressed Also, there is usually no perceivable audible sound, such as a "click" heard by a discrete key.
The lack of such sensory responses causes a user to be uncertain that individual keys have been depressed sufficiently to produce a character. Thus, the user can become frustrated and is oftentimes unable to enter information in a fast and efficient manner. Therefore, it would be highly desirable to have a new and improved membrane keyboard having audible and tactile feedback responses to alert the user when the key was properly actuated to enter the desired information.
Another reason for the poor acceptance of the membrane keyboard in many applications, is not only the lack of perceivable audible and tactile feedback, but also because the membrane keys are substantially flat. In this regard, it has been generally recognized that for rapid and efficient keyboard entry purposes, different keys should have different vertical heights and be positioned at different angles, so the user can conveniently reach all of the keys on the keyboard Such non-uniform positioning of keys is required in part because of the physical structure of the hands and fingers of the user, as well as the different finger-to-key strokes utilized for rapid keyboard entry. Thus, for efficient use of a keyboard, the individual character keys should be arranged in rows having discrete height differences to provide the keyboard with an overall generally dished working surface. Since membrane keys are substantially flat, they do not lend themselves to forming such a dished surface, which is important for helping provide a more efficient keyboard operation.
Additionally, as more fully described in the foregoing mentioned co-pending application, prior known conventional keyboards, including membrane or planar keyboards can cause physiological injury to the user, after repeated use over long periods of time. Such repetitive stress injuries are collectively referred to as cumulative trauma disorder. Thus, the new and improved keyboard and method of using it should help relieve stress and thus help prevent physical injuries to the user. This should be accomplished without cumbersome, mechanical adjustments of the keyboard housing. Moreover, at the same time, it should be constructed to facilitate fast and accurate keyboard entry, so that a new user can quickly learn to use such a new membrane keyboard, with little or no unwanted time consuming delays. In this regard, some one who is trained in touch typing techniques, should be able to use such a new membrane keyboard with little or no training.
Therefore it would be highly desirable to have a new and improved membrane keyboard, which would be comfortable to use in a fast and convenient manner, and which could be used in a less physiologically stressful manner.